ab cd Case Introduction A 63-year-old male patient underwent a left-sided discectomy of L5/S1 for an S1 radiculopathy. After a pain free interval of 5 months, he presented again with severe recurrent left sided leg pain predominantly at the posterolateral aspect of the calf. An MRI scan showed a small recurrent sequestrated disc herniation at the level previously operated on ( a, b). The patient was referred to a neurologist because the clinical findings and the imaging study did not completely match. A detailed history revealed that the patient reported pain in the lower back down to the left calf and heel. However, he additionally felt numbness in the thoracoabdominal skin on the left side. The neurological examination revealed an absent left Achilles tendon reflex, hypesthesia of the left T6–T10 and S1 dermatomes but no paresis. The L5 dermatome presented petechial efflorescence ( c, d). The EMG of the gastrognemius muscle confirmed chronic denervation as a sign of a radicular lesion probably caused by the disc herniation of the S1 root. However, prolonged tibial somatosensory evoked potential, hypesthesia of the thoracic dermatomes as well as the dermatomal efflorescence suggested an addi- tional neurological disorder. The suspected diagnosis of a herpes associated myelitis was confirmed by pathological anti- body titers against herpes zoster virus, and increased cell count (65/μl) and protein level (1.66 g/l) in the CSF. The patient was treated with acyclovir (i.v. application over 5 days and continued oral medication for 3 months). Three months later the pain had completely subsided and the patient regained full neurological function. 292 Section Patient Assessment Always differentiate radiculopathy and peripheral neuropathy Peripheral neurological disorders may mimic radiculopathy and should be dif- ferentiated by the neurological examination and complementary neurophysio- logical tests. Entrapment syndromes are easily confused with radiculopathy For example, polyneuropathy can cause similar symptoms to lumbar stenosis. While the clinical examination might not be sensitive enough to distinguish between both disorders, neurophysiological testing (nerve conduction and reflex studies) can confirm the presence of a polyneuropathy. There are no reliable data available on the prevalence of polyneuropathy in a general population and the reported percentage ranges between 7% and 57% [120]. About 50% of patients with diabetes and 60% of patients with alcohol addiction suffer from polyneu- ropathy, indicating the importance of an extended differential diagnosis in this patient population when patients present with back and leg pain [32, 88, 90, 122]. Entrapment syndromes frequently show similarities to radicular syndromes. The carpal tunnel syndrome (CTS) is the most frequent entrapment (6% in a general population) syndrome and occurs twice as often as the compression syn- drome of the ulnar nerve [8, 9, 27, 28, 106]. Similar in symptoms, but less com- mon, is the thoracic outlet syndrome (TOS), occurring in not more than 1% in a general population [79]. The counterpart of the CTS is the tarsal tunnel syn- drome of the foot, which is much rarer than the CTS. In electromyography (EMG) laboratories the incidence is reported to be lower than 0.5% [78, 80]. The C5, C6, L5 and S1 nerve roots are most frequently affected Due to the different vulnerability of specific nerve fibers and spinal cord tracts, typical clinical syndromes are frequently observed both in degenerative and in traumatic spinal disorders. Degenerative disorders, particularly spinal stenosis and disc herniation, most frequently occur in the cervical and lumbar spinal seg- ments due to the biomechanical spine properties (anatomical characteristics) and dynamic/static forces acting on these segments. While a cervical spinal stenosis can result in cervical myelopathy with clinical signs of impaired longitudinal tracts (spasticity of lower limbs, numbness of feet), lumbar spinal stenosis can affect the cauda equina causing neurogenic claudication. Radiculopathies are mainly due to disc herniation and to hypertrophic facet joints. The most frequent cervical radicular lesion is the radiculopathy of C5 and C6, whereas in lumbar radiculopathy the L5 and S1 roots are most frequently involved [17, 38, 102, 128]. Furthermore, in 16% of patients (study of 585 patients screened in a regional UK clinical neuroscience center) with a non-traumatic para- or tetraparesis, a meta- static or primary spinal tumor could be diagnosed [82, 112]. Traumatic spinal disorders (e.g. spinal cord injury, SCI) are mainly caused [30] by: motor vehicle accidents (40–50%) sports accidents and falls (20–30%) assaults (gunshot and stabbing) (5–20%) occupational injuries (10–20%) Patients suffering from traumatic SCI are mainly young (average age 38 years) and male (male:female ratio = 4:1), while there is a second age peak between 60 and 80 years due to predominantly falling injuries [30, 34, 39, 56, 100, 118, 124]. The incidence of traumatic SCI (10–30/million) varies between countries with a slightly higher number of incomplete SCI and tetraplegia versus paraplegia (for reference see: www.spinalcord.uab.edu). While spontaneous (osteoporotic) com- pression fractures of the vertebral column rarely show neurological deficit, burst fractures of the cervical and thoracic spine are commonly associated with severe neurological deficits [4, 12, 21, 71, 72, 119]. About 55 % of patients with SCI suffer from tetraplegia In patients with SCI, the cervical vertebral column is the most frequently injured spine segment resulting in incomplete tetraplegia in 34.3% and complete tetraplegia in 22.1% of cases. Neurological Assessment in Spinal Disorders Chapter 11 293 In mid-thoracic traumatic fractures, patients mainly suffer from complete para- plegia while fractures at the thoracic-lumbar junction show an incomplete lesion in more than half of the patients [42, 119]. Anatomy and Somatotopic Background The spinal cord represents the only connection of neurological structures between body and brain for the conduction of motor, sensory and sympathetic- autonomous information. The parasympathetic innervation bypasses the spinal cord via the vagal nerve originating from the brainstem. Longitudinally oriented spinal tracts (white matter) surround central areas (gray matter) where neuronal The cell bodies of the motoneurons are located in the gray matter cell bodies are located (Fig. 1). Sensory axons entering the dorsal part of the spi- nal cord originate in the dorsal root ganglia, which are located outside the spinal cord. Along with the motor axons originating from the central part of the spinal cord, they leave the spinal segment through the intervertebral foramen at every segment. Furthermore, it is important to realize that the motor synapses between the first and the second motoneurons are located in the ventral part of the gray The cell bodies of the sensory neurons are located in the dorsal root ganglion matter (alpha-motoneuron), whereas the neuronal cell bodies of the peripheral sensory neuron are situated in the dorsal root ganglion within the intervertebral foramen. In the cervical spine there is one pair of cervical nerve roots more than verte- brae bodies. Therefore, the anatomic relationship changes at the cervicothoracic junction. While in the cervical spine the C4 nerve root exits the C3/4 foramen, the L4 nerve root exits the L4/5 foramen in the lumbar spine. In the cervical spine, the cell bodies of the alpha-motoneuron are located approximately one level higher than the exiting nerve root. This is of clinical relevance as focal damage to the anterior spinal cord can cause a more distal deficit than one would expect from the location [25]. Essential anatomical landmarks of the somatotopic orga- nization of the spinal cord are: Figure 1. Somatotopic organization of the spinal cord 294 Section Patient Assessment the posterior column containing sensory nerve tracts conducting position sense (proprioception) and awareness of deep pressure the ventrolateral column contains spinothalamic tracts for the sensation of pain and temperature the posterior-lateral tract transmitting voluntary motor control through the pyramidal tract Classification A straightforward differentiation of neurological impairment is related to the cause and onset of the disorders and basically distinguishes between: traumatic injuries non-traumatic disorders Spinal disorders can further be differentiated with regard to the affected neuro- nal structures, i.e.: central (CNS) nervous system peripheral (PNS) nervous system A CNS lesion indicates a compromise of the brain or spinal cord, i.e. longitudinal spinal tracts. In contrast, a PNS lesion includes impairment of all the neural structures outlying the spinal cord, i.e. ventral nerve roots and cauda equina nerve fibers within the spinal canal. Therefore, a lesion of the conus medullaris with degeneration of the alpha-motoneurons or the cauda equina shows typical clinical findings of PNS involvement while a lesion higher within the spinal cord mainly presents as a central sensorimotor deficit. Non-traumatic spinal disorders can be differentiated as listed in Table 1. Focal compression syndromes predominantly occur in the cervical or lumbar spine Focal compression syndromes of the spinal cord in degenerative disorders are predominantly localized at the cervical and lumbar spinal level [3, 6, 92, 115]. Here, the spine has to cope with the highest biomechanical stress (a high range of motion and being under great strain during daily activities) and is prone to develop a degenerative stenosis resulting either in cervical myelopathy or lumbar spinal canal stenosis and neurogenic claudication. Furthermore, the cervical spi- nal canal can show a congenitally reduced diameter with increased vulnerability to degeneration or even minimal cervical trauma with severe neurological sequelae [107, 115, 130]. Cervical spinal canal stenosis due to obliterating hyper- trophy of the occipital posterior longitudinal ligament (OPLL) and less frequently in the thoracic spine can also induce spinal cord compression even in younger patients [48, 53, 77, 129]. Spine tumors of different etiology (intra- or extradural) and dignity always have to be considered in patients assumed to suffer from spinal disorders [1, 44, 66, 81]. Spinal hemorrhages predominantly occur acutely/spon- taneously in patients undergoing anticoagulation treatment, or suffering from tumors or arteriovenous malformations [37, 58, 83, 91, 114, 116, 126]. While spine compression, tumors and hemorrhages can be reliably diagnosed by imaging (preferablybyMRI),theischemic, infectious, and degenerative disorders need a thorough work-up to conclude the specific diagnosis [10, 46]. In atypical cases also consider non-spinal differential diagnosis Specifically in cases with atypical presentation, disorders other than those of the spinal cord have to be considered in the differential diagnosis. Similarly, in older and multi-morbidity patients, peripheral nerve disorders can be confused with spinal cord disorders and have to be specifically addressed. In patients with a slowly developing polyneuritis, an increasing motor weakness, reduction of walking distance and occurring pain can mimic a lumbar spinal stenosis, while neurophysiological testing can be applied to distinguish between both disorders. Neurological Assessment in Spinal Disorders Chapter 11 295 Table 1. Classification of non-traumatic neurological syndromes Impaired neuro- logical structure Cause of impairment Major symptoms Spinal cord compression disc herniation severe pain para-/tetraparesis bowel/bladder dysfunction congenital cervical stenosis clumsy hands with reduced dexterity ataxic gait degenerative cervical stenosis bladder dysfunction micturition problems (urgency, frequency) ossification of the posterior longitudinal ligament (OPLL) pain slowly developing myelopathy radiculopathy (frequently) lumbar spinal canal stenosis neurogenic claudication low back pain Spinal cord tumor extramedullary intradural tumor (neuri- noma, meningeoma, schwannoma) pain syndromes progressive tetra-/paraparesis bladder-bowel dysfunctionextramedullary extradural (metastases, lymphoma) intramedullary tumor (ependymoma, astrocytoma) Spinal hemorrhage spontaneous hemorrhage (AV malfor- mation, cavernoma, anticoagulation) sudden onset acute girdle pain increasing tetra-/paraparesis Ischemic spinal cord lesion ischemia of anterior spinal artery (arteria sulcocommissuralis) girdle-like pain prior to weakness central cord syndrome spinal cord malacia (arteria radicularis magna Adamkiewics) acute paraplegia AV malformation intermittent claudication Demyelinating disorders multiple sclerosis recurrent episodes or primary chronic course of sensorimotor deficits visual disturbance acute demyelinating encephalomyelitis (ADEM) acute onset cerebral symptoms associated with sensorimotor deficits (mostly after viral infection or vaccination) transverse myelitis acute onset with rapid and profound deficits no clear association with viral infection or other demyelinating CNS disorders neuromyelitis optica (Devic syndrome) fulminating progressive para-/tetraplegia loss of vision Infectious myelitis viral (HSV, HIV, HTLV, EBV, Coxsackie virus, echovirus, poliomyelitis) bacterial and fungal initial girdle-like pain progressive para- or tetraplegia spastic spinal paralysis Physical myelopathy radiation/electrical spinal cord damage postradiation symptoms (early or late) beginning with pain variable syndromes Hereditary/sporadic degeneration of spinal pathways variable mutations of genes, amyotro- phic lateral sclerosis mainly associated with spastic paraplegia variable sensory loss muscle atrophy bladder dysfunction A mismatch of clinical find- ings and imaging studies must prompt a thorough neurological assessment Therefore, in patients where the radiological and clinical findings are not fully in line with the patient complaints or imaging findings, a thorough neurological work-up should be initiated ( Case Introduction). For example, the first clinical symptom of a diabetic neuropathy can appear as a severe painful affection of the femoral nerve with a marked paralysis of the quadriceps muscle. This symptom can be easily confused with an L3 radiculopathy and the mismatch between an extensive clinical picture (weakness, loss of reflexes and sensory deficit) and nor- mally appearing lumbar imaging should indicate a further work-up. 296 Section Patient Assessment Figure 2. Standard neurological classification of spinal cord injuries (ASIA) In traumatic spinal cord injury the main classification distinguishes between: paraplegia tetraplegia The term “paraplegia” refers to the impairment or loss of motor and/or sensory function in the thoracic, lumbar or sacral (but not cervical) neural segments (T2–S5). Impairment or loss of motor and/or sensory function in the cervical segments (C0–T1) is called tetraplegia. In accordance with the standard neuro- logical classification of spinal cord injury ( Fig. 2) of the American Spinal Injury Association (ASIA), the defined muscles and sensory examination points should be assessed for diagnosis [68]. A further differentiation is made with regard to the completeness of the lesion as: complete incomplete The preservation of lower sacral segments indicates an incomplete lesion The distinction between complete and incomplete is based on the preservation of any sensory or motor function within the last sacral segments S4–S5. The ASIA impairment scale (AIS) allows a further grading ( Table 2)ofthecompletenessof the lesion [67, 70]. Neurological Assessment in Spinal Disorders Chapter 11 297 Table 2. ASIA Impairment Scale ASIA A sensory and motor complete ASIA B sensory incomplete, motor complete ASIA C sensory and motor incomplete, motor function below the level of lesion in mean M3 ASIA D sensory and motor incomplete, motor function below the level of lesion in mean >M3 ASIA E no relevant sensorimotor deficit, minor functional impairments of reflex-muscle tone changes Neurological Assessment Complementary to the physical and radiological examination of the spine, the neurological examination focuses on identifying: the level of the lesion the extent of neural compromise A detailed history enables an initial broad diagnosis (involvement of upper ver- sus lower limbs, time of onset, trauma) and the neurological examination deter- mines more precisely any possible spinal cord damage. The clinical examination can be complemented by additional neurophysiological studies particularly when the clinical examination is limited due to poor cooperation by the patient. The following clinical symptoms should be distinguished by the examiner: motor weakness sensory deficit altered reflexes (cave: spinal shock) pain syndromes autonomic functions (bowel and bladder dysfunction) The examination can allocate the symptoms to neurological syndromes such as: radiculopathy polyneuropathy myelopathy central paresis Neurological syndromes are non-specific for the underlying pathology However, neurological syndromes are non-specific with regard to their spinal cause, e.g. a radiculopathy can be caused by a disc herniation, an osseous spur, or a synovial facet joint cyst. From a practical point of view, it is reasonable to differ- entiate the assessment of patients with and without trauma and the course of symptom onset (acute versus slowly progressive). This differentiation is not always self-evident and has to be specifically identified. Pain Pain is the most frequently complained of symptom which can lead one to the impaired neurological structure [49, 95, 108]. The pathophysiology and diagnos- tic assessment of pain are covered in Chapters 5 and 40 . Sensory Deficits Distinguish the sensory qualities (light touch, pin prick, proprioception) Although multiple sensory qualities (heat–cold, pain, touch, pressure, static and dynamic two-point discrimination, vibration sensation) can be distinguished, the examination of: light touch pinprick proprioception 298 Section Patient Assessment is most frequently applied in clinical practice to assess spinal cord dysfunction [13, 41, 51, 62, 84, 89, 99, 101]. While the light touch sensation assesses the per- ception of touch as applied by the finger or cotton wool, the pinprick sensation identifies the ability to sense a sharp needle tip. The latter function is transmitted via the spinothalamic spinal pathway and the actual examination does not pro- duce different levels of pain. The key is that the patient identifies a sharp sensa- tion, which is not necessarily painful. The vibration sense is reliably tested with a tuning fork that allows different grades of vibration recognition to be distin- guished [45, 86, 98, 99]. It is important to be aware that particularly incomplete lesions of the spinal cord can cause more diffuse distributed sensory deficits whereas radicular and peripheral lesions result in circumscribed changes. Patients with cervical mye- lopathy often complain of pain, clumsiness and numbness of the whole hands and/or feet. Consider central lesions in diffuse/dissociated sensory deficits In ischemic lesions of the central part of the spinal cord, the predominant clin- ical finding is an impairment of pain and temperature sensation. In such cases, sensation to touch remains preserved while pain and temperature sensation is abolished, which is typically distributed in a segmental pattern. The affection of the posterior column as induced by a B 12 hypovitaminosis or rarely due to trauma causes a reduction of the vibration sense with predominant gait disturbance. Motor Deficits The differentiation of the causes of muscle weakness can sometimes cause diag- nostic difficulties. In general the following lesions should be distinguished: peripheral lesion radicular lesion central lesion The muscle force should be assessed according to a standardized protocol either following the guidelines of the British Medical Research Council or as modified by the ASIA Standards (see Chapter 8 ) [70]. Amonoparesisofupperorlowerlimbsisfrequentlycausedbyaplexuslesion. Radicular lesions are typically associated with pain emanating into the respective dermatomes and show paresis of the innervated muscles. The differentiation between radicular and peripheral nerve lesion is sometimes difficult (see below). Painless muscle atrophy demands a detailed neurological differential diagnosis A painless atrophy of hand or foot muscle always demands a neurological work-up and an extended differential diagnosis has to be considered: amyotrophic lateral sclerosis spinal muscular atrophy myelopathy neuropathy (hereditary motor neuropathies) Reflex Deficits The clinical examination of upper and lower limbs as well as sacral reflexes is mandatory in the assessment of spinal disorders. Reflexes are not only helpful in defining the level of lesion but also in distinguishing acute versus chronic Screen for central lesions using reflex assessments changes. Besides the muscle tendon reflexes, various signs (Figs. 3, 4)andmuscle tone testing (clonus, stiffness) are used to screen for pyramidal tract or conus lesions [5, 18, 23, 36, 43, 54, 64, 75, 85, 104, 127]. Neurological Assessment in Spinal Disorders Chapter 11 299 a b c d e f Figure 3. Signs (reflexes) indicating pyramidal tract lesions a Babinski sign. b Oppenheim sign. c Gordon sign. d Rossolimo sign. e Trömner sign. f Hoffmann sign. The Hoffmann and Trömner signs can be observed in healthy individuals with hyperexcitability and are only pathologic if they occur unilat- erally or in very pronounced fashion. 300 Section Patient Assessment ab cd Figure 4 . Polysynaptic reflexes a The absence of the anal reflex indicates a lesion at S3–5. b Absence of the abdominal reflex indicates a lesion at T7–12 (screening test for patients with putative idiopathic scoliosis). c Absence of the bulbocavernosus reflex indicates a conus medullaris injury. After acute spinal cord injury, the bulbocavernosus reflex can be elicted within 72 h even in spinal shock in contrast to the lower limb tendon reflexes. Recovery of the bulbocavernosus reflex without sensory or motor function indicates a complete spinal cord lesion. d Absence of the cremaster reflex indicates a lesion at the level of L1/2. Gait Disorders Gait disorder should be detailed by questioning and clinical tests. Ataxic gait with increased danger of falls (impaired balance and ability for line walking), need for Gait disorders must be thoroughly differentiated an enlarged support base, and increased difficulty in walking in darkness are signs of disturbed proprioception. That may be caused (with decreasing fre- quency) by: polyneuropathy posterior column disorders cerebellar lesion Neurological Assessment in Spinal Disorders Chapter 11 301 . in degenerative and in traumatic spinal disorders. Degenerative disorders, particularly spinal stenosis and disc herniation, most frequently occur in the cervical and lumbar spinal seg- ments. whereas radicular and peripheral lesions result in circumscribed changes. Patients with cervical mye- lopathy often complain of pain, clumsiness and numbness of the whole hands and/ or feet. Consider. of the central part of the spinal cord, the predominant clin- ical finding is an impairment of pain and temperature sensation. In such cases, sensation to touch remains preserved while pain and